A method for estimating movements of a crowd between a first and second subregion in an area are monitored by a wireless sensor network. The wireless sensor network includes nodes configured to exchange a radio frequency signal through a first respective second link. The first respective second link crosses the first respective second subregion. The method includes the steps of exchanging radio frequency signals over the first and second link; and measuring respective first and second attenuations of the exchanged radio frequency signals over the first respective second link; and estimating based on a change in the attenuations a flow of the crowd between the first and second subregion. The estimating further includes estimating based on the first and second attenuations a density of the crowd in the first respective second subregion; and estimating based thereon a flux of the crowd between the first and second subregion.